I have a burning question ; A Dreamscape is basically a world calculated in our brains, right? Since the brain is only so big, is the dreamscape only so big? Or can you run off into something forever in a dream? Are there 'Invisible walls' in our dreams?

Most dreams fade out after a while, so yes there are limits. One LD in particular, I decided to fly really fast, superman style. To my astonishment the dream environment "generated" itself really fast and in great detail. I couldn't remember many of the details afterwards though. After only a couple seconds of flying that way, suddenly a huge building "popped up" in front of me and I crashed into it. I was lying in the middle of a bunch of rubble, I looked up and saw a DC smiling at me. Then I woke up.

That's a good one. Dreams are created in our unconscious mind. We don't know much about our unconsciousness, only that it's huge. It's not limitless I think, something that goes towards infinity is something strange for me. The idea of infinity is strange to me already. I think it's just like the universe, immensely big, but limited. There will be a point where your unconsciousness can't keep up and stop.

I am not quite sure of this, this came out as I was typing, but it's definitely a interesting subject!_________________Fantasy is endless

Hahaha, nice thought. Let's honestly think about it though. Yes, our minds have limits. Yes, there are time limits within a dream (although some have said that they are able to live for far longer periods of time in the dream than their actual sleep-time).
So if there are time limits in a dream, are there space limits?
The answer is yes. The only dreamworld being generated is the area with which we are in direct contact, for example, the area we can see. There is no need for the dreamworld to exist outside this field of vision or contact. It is kind of like in a free-roaming game like Minecraft or Skyrim where the world loads around you as you travel, except in a dream you can't see your mind spawning the grass in the distance because your mind is a far more powerful as an information processor than any computer.
So think about it. The dream is only the sphere of vision around you. It's like being in the centre of a bubble, and that bubble is the dreamworld. When you move in a certain direction, the bubble moves with you, so you never move from the centre. Within this bubble is the dreamworld being created and displayed by the mind. There is no need to create the dreamworld outside this sphere of vision so it does not exist until you walk down the road. Then, the bubble would travel with you and create the road within your vision. If you can see far into the distance, obviously, the bubble will be larger, so that it can contain the entire field of vision. If you are in a small room, the mind is only creating the room, nothing exists outside it until you open the door and the bubble travels with you to create the outside corridor, expanding if necessary due to you being able to see further.
This theory works, because the mind has limits, and this way it only has to create or process small areas, that which you can see. The dreamworld isn't an infinite expanse that exists at all times no matter where you are. It's just your bubble of experience. So the dreamworld would go on forever, because all your mind has to do is create the world immediately around you as you travel. And eventually, you will wake up, because although the dream is a bubble of created space, it is not a bubble of created time... or is it? That's for another time. I personally think that it is possible to manipulate the time within your dreams to make them last longer, but that's irrelevant to this topic. Hope this helps answer your question!

What do you mean? I'm just saying that nothing need exist outside of our range of perception. A dream is not a concrete place, it does not stay the same as it is a construct of your subconscious mind. A dream is not a solid thing. Sections of the dream world will remain the same if you expect them to, but dreams do change, so each night you generally enter a new dreamworld, or a new section of it.
By the "bubble" I wasn't implying that dreams were any different in nature to what we alreeady know, just that since we can't see anything beyond our immediate dreamworld, there is no reason for an infinite continuation to exist, nor any evidence that it exists beyond an illusory sense of "the beyond".
A dream is a set of illusory perceptions residing in our immediate sphere of interaction. While we are in a certain place, our dream is creating the immediate perceptions within the bubble of sight. Everywhere beyond that point is either being stored as a concept in the back of our dreaming minds, or simply doesn't exist until we walk there.
So in answer to your question, yes, mostly the place would be the same. Like if I'm standing on one side of a building in the dreamworld, and have no idea what is on the other side. The other side doesn't exist until I walk around the corner and my mind generates it from various schemata: trees, footpaths, a classic urban area. Now that I'm on this side of the building, and the original side is out of sight, the original side doesn't exist. However it remains in my memory and mind as a concept: I remember what it was LIKE around the corner, it just isn't actually THERE until I walk back around the corner. So when I do walk back around the corner to my original position, my mind will recall what it is expecting to see (ie. what was there before). So parts of the dreamworld are either existent in our sphere of perception, non-existent and only to become existent if I actually travel there (where they will be randomly generated), or they exist as a concept based on previous interaction with the place itself within the same dream).
You could kind of imagine the dreamworld like a hamster wheel with the inside of the wheel painted like a landscape. As you run through the dreamworld or around the hamster wheel, the world around you is being generated and fed through to you. Meanwhile, the landscpe that you have just run past does not sit in existence behind you: It ceases to be, or rather, saves as a concept and then rotates over the top of the wheel to be used again in front of you. I'm not saying that scenery in dreams is on a loop, I'm just saying that because the scenery you have passed does not need to exist, it allows the calculating space that the visual spectacle takes up in your mind to be filled in with the new information coming in in front of you. So your mind never runs out of space: it only has to graphically represent what is in your sphere of vision: anything you have passed it can stop creating and use the space to focus on creating the dreamworld that you're percieving as it changes.
It's kind of hard to explain... it's not even really a bubble, because you can't see what's behind you, so what is behind you doesn't exist either (until you turn around). It's more of a cone or a hemisphere of vision.
So sometimes the places you return to will be the same, as your brain has remembered what they looked like, but often there will also be changes, due to the random and unstructured nature of dreams, and sometimes places that you return to can be different altogether.
What Lence was talking about was a time limit to the dream, or a limit to the amount of excitement or brain activity that your mind can sustain in a lucid dream. If he hadn't woken up he could have potentially kept going for ages longer, unless you're EXPECTING there to be an edge to the dreamworld, in which case you may find one (still, you could break through that and continue, if you had enough willpower). But maybe that's why we break up our dreams throughout the night: your brain wouldn't want to be constantly spawning and creating a dreamworld for ten hours straight I'm sure!

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